Warning Brisk LPG spark plugs

[Clan]

The idea of multi prong plugs is indeed ONLY long life , basic electronics say the spark will always take the easiest path , it is impossible for the plug to have multi sparks on each prong at the same time unless it is fed with huge amounts of HT energy..
what happens is that the spark takes the path of least resistance which is the prong with the shortest gap , as this wears, the gap gets wider and eventualy the next unused prong is the easiest path and that one starts to get used , and likewise until that wears and the third prong starts to get used etc , that is how volvo plugs last 72000 miles ..
You may choose your particular plugs that work right with your LPG, however if you use it on petrol often you will find the genuine volvo plugs give the best performance of all . Volvo ignition systems are and always have been very powerful and really should cope with lpg , they always did fine in the 1980s-1990's-2000's what's changed ? .. I guess genuine volvo plugs were not tried first on this problematic engine ..